Mobile and/or wireless electronic devices are becoming increasingly popular. For example, mobile telephones, smart phones, tablet computers, portable media players and portable gaming devices are now in wide-spread use. In addition, the features and accessories associated with certain types of electronic devices have become increasingly diverse. To name a few examples, many portable electronic devices, such as mobile phones, have cameras, text messaging capability, Internet browsing capability, electronic mail capability, video playback capability, audio playback capability, image display capability and handsfree headset interfaces.
In a wireless or mobile communications system (collectively sometimes referred to below as mobile communications system) a network having a base station (sometimes referred to below as a network base station) may be in communications with one or more terminals. The base station typically is at a fixed location and the terminal(s) typically are portable and movable to and within a cell that is defined by the communications area covered by the base station. Downlink, downlink communications and downlink transmission, for example, refer to transmission from a base station to a terminal; and uplink, uplink communications and uplink transmission, for example, refer to transmission from a terminal to a base station.
A terminal used in a mobile communications system can be equipped with more antennas than transmission chains. One example is a terminal having two antennas due to utilizing downlink receive diversity, e.g., downlink 2×2 MIMO (multiple input multiple output), while the uplink only uses one transmission chain. This enables a selection possibility within the terminal what antenna(s) to utilize for the downlink transmission chain(s). If the terminal can dynamically switch what antenna(s) to utilize from the downlink transmission chain(s) for a given time, this can be denoted as adaptive antenna selection. Use of a 2×2 MIMO downlink, for example, can increase system throughput from a base station to a terminal.